DP Chemistry (first assessment 2025)
Question 22M.2.HL.TZ2.7a(i)
| Date | May 2022 | Marks available | [Maximum mark: 1] | Reference code | 22M.2.HL.TZ2.7a(i) |
| Level | HL | Paper | 2 | Time zone | TZ2 |
| Command term | State | Question number | a(i) | Adapted from | N/A |
a(i).
[Maximum mark: 1]
22M.2.HL.TZ2.7a(i)
(a(i))
State why NH3 is a Lewis base.
[1]
Markscheme
donates «lone/non-bonding» pair of electrons ✔
Examiners report
The main error was the omission of lone electron "pair", though there was also a worrying amount of very confused answers for a very basic chemistry concept where 40% provided very incorrect answers.
Syllabus sections
Reactivity 3. What are the mechanisms of chemical change? » Reactivity 3.4—Electron-pair sharing reactions » Reactivity 3.4.6—A Lewis acid is an electron-pair acceptor and a Lewis base is an electron-pair donor. Apply Lewis acid–base theory to inorganic and organic chemistry to identify the role of the reacting species.